Micro personal digital assistant with a compressed BIOS system

ABSTRACT

A personal digital assistant module with a local CPU, memory, and I/O interface has a host interface comprising a bus connected to the local CPU and a connector at a surface of the personal digital assistant for interfacing to a bus connector of a host general-purpose computer, providing direct bus communication between the personal digital assistant and the host general-purpose computer. In an embodiment, the personal digital assistant also has a means for storing a security code. The personal digital assistant according to the invention forms a host/satellite combination with a host computer having a docking bay, wherein upon docking a docking protocol controls access by the host to memory of the personal digital assistant based on one or more passwords provided by a user to the host. In another embodiment the personal digital assistant has a compressed BIOS chip, and in yet another embodiment also has an expansion port connected to the local CPU, and expansion peripheral devices may be connected and operated through the expansion port.

CROSS REFERENCE TO RELATED DOCUMENTS

[0001] The present application is a divisional of application Ser. No.09/785,574 which is a continuation of application Ser. No. 08/683,567which is a continuation-in-part of application Ser. Nos. 08/144,231 and08/019,592.

FIELD OF THE INVENTION

[0002] This invention is in the area of portable computers and pertainsmore specifically to small portable computing devices known in the artas personal digital assistants, and to Basic Input/Output Systems (BIOS)for such devices.

BACKGROUND OF THE INVENTION

[0003] Personal Digital Assistant (PDA) units, as of the date of thisdisclosure, enjoy a position of hope in the computer marketplace. Somebelieve this approach, a small, relatively inexpensive, and eminentlyportable computer unit, having software specifically written for tasks auser might expect to perform while traveling, will provide eminentlyuseful and therefore salable computer products. Apple Computer, HewlettPackard, and several other well-known computer manufacturers have made aconsiderable investment at no small risk in such systems.

[0004] Given the new systems now introduced, and those coming, for whatis now known about them, there are still a number of drawbacks andproblems. For example:

[0005] 1. The PDA systems introduced are relatively costly, withstarting prices ranging from several hundred dollars to two thousanddollars and more. At such prices, rivaling current pricing for desktopsystems, the buying public may react negatively. It is true that priceswill fall with increased manufacturing volume and competition, but thehigh end start may well be rejected by potential users.

[0006] 2. The systems being offered are still relatively bulky,considering the limited range of tasks that may be accomplished. Mostare certainly too big to be conveniently carried in a breast pocket. TheNewton, manufactured by Apple Corporation, weighs about a pound and isapproximately the size of a VHS video cassette.

[0007] 3. A big drawback of the PDA systems being offered is the waythey transfer data between a user's desktop unit, or other host, and thePDA. Known communication is by modem, by infrared communication, and byserial connection. These all require manipulation by a user, modulationon one or both ends of the communication path, and the like, which canbe time-consuming, error-prone, and hardware extensive (expensive).Presently the Newton offers a modem and/or LED communication as anoption, adding to the overall cost.

[0008] 4. In known PDAs, software is typically recorded in ROM, soupdating applications can be difficult, and sometimes impossible. Thiswill be a problem because PDA users will not want the PDA to have thesame capabilities at all times. Typical users will be people who traveland work while they travel. These users require different functions fora trip to Taiwan than for a trip to France, for example. What is neededis a quick and convenient means to update and substitute software.

[0009] 5. Another difficulty is in the fact that the data files a usermanipulates while traveling are typically data files also resident in ahome unit, herein called a host unit, such as the user's office desktopmachine or notebook or other portable computer. It is very troublesometo have two or more sets of critical data, with differences that onemust remember to correct at an appropriate time. This can cause unendinggrief if files are not correctly updated. At best, current PDAs must usea relatively slow compressed bus to download and upgrade files.Typically this is done through a serial port, using a linkingapplication like Laplink™.

[0010] 6. Yet another difficulty with small devices like digitalassistants is in providing embedded code routines, such as BIOSroutines, in a minimum read-only memory (ROM) real estate. There is aconsiderable motivation to provide routines embedded in ROM, because ROMis relatively inexpensive, and always a requirement for minimum size andcost.

[0011] What is needed is a small and inexpensive PDA that has a range offeatures that eliminate the above-described risks and problems. This newunit needs to be smaller than those presently being introduced, such asabout credit-card size, or perhaps modeled on the PCMCIA type II or typeIII standard form factors. It should be inexpensive enough to producethat at least a minimum version could be sold in the roughly $100-$200range, so it will be a unit seen to be a relatively inexpensivenecessity. A PDA unit of this sort is the subject of the presentinvention, and is termed by the inventors a micro-PDA, or μPDA.

[0012] A very important feature of the μPDA in an aspect of the presentinvention is a direct parallel bus interface with a connector allowingthe unit to be docked by plugging it into a docking bay in a host unit.Moreover, when the μPDA is docked in the host, there needs to be a meansto effectively disable the CPU in the μPDA and to provide direct accessto both the μPDA software and data storage by the host CPU. This directaccess would provide immediate ability to communicate in the fastestavailable fashion between the μPDA and the host, and would alsofacilitate additional important features to be described below.

[0013] The μPDA also needs to have an optional compressed bus interface,including a connector separate from the host interface, so add-ondevices may be utilized, such as a FAX modem, cellular communication,printer, and so on.

[0014] An additional feature that could be optionally provided inanother aspect of the invention is an interface at the host to allow auser to select pre-arranged software mixes for loading to the μPDA. Thisfeature comprises a set of control routines operating in conjunctionwith the host's display and input means, to allow the user to quicklyselect applications and perhaps data as well to be loaded to the μPDAsatellite, to configure the smaller, more portable unit for specificitineraries and purposes.

[0015] Another desirable feature is an ability to automatically updatedata files. In this aspect of the invention, with the μPDA docked, dataon the host, if carrying a later date and/or time stamp than the data onthe μPDA, would be automatically updated on the μPDA and vice-versa.When one returns from an excursion using the μPDA and docks thesatellite at the host, the host gains access, determines the location ofthe latest files, and accomplishes the update. This feature needs tohave some built-in user prompting to be most effective. It makes theμPDA a true satellite system.

[0016] In addition to the above, it is also desirable that the μPDA beserved with code embedded in one or more ROM chips in a manner to allowmore code to be provided than the apparent capacity of the ROM.

SUMMARY OF THE INVENTION

[0017] In a preferred embodiment of the invention a personal digitalassistant module is provided comprising an enclosure for enclosing andsupporting internal elements, a microcontroller within the enclosure forperforming digital operations to manage functions of the personaldigital assistant module, and a memory means connected to themicrocontroller by a memory bus structure for storing data andexecutable routines. There is a power supply means within the enclosurefor supplying power to functional elements of the personal digitalassistant module, a display means operable by the microcontroller andimplemented on a surface of the enclosure, and input means connected tothe microcontroller for providing commands and data to the personaldigital assistant module. A host interface means comprising a hostinterface bus structure, which may be configured as a PCMCIA businterface, is connected to the microcontroller and to a first portion ofa host interface connector at a surface of the enclosure, and the hostinterface means is configured to directly connect the microcontroller toa compatible bus structure of a host computer.

[0018] In an embodiment, the personal digital assistant module has aBIOS embedded in ROM in a compressed fashion, along with an uncompressedportion for testing and initializing system memory on start-up, and anuncompressed compression utility routine configured for decompressingthe compressed BIOS portion.

[0019] In another embodiment the personal digital assistant module hasan expansion bus interface comprising an expansion bus structureconnected to the microcontroller and to a first portion of an expansionbus connector for connecting the microcontroller to a peripheral device.A wide variety of peripheral devices are provided for use with thepersonal digital assistant of the invention.

[0020] In another aspect, the personal digital assistant module also hasa nonvolatile storage device, such as an EEPROM connected to themicrocontroller and containing one or more codes unique to the personaldigital assistant, for uniquely identifying the personal digitalassistant to digital devices connected on the host interface.

[0021] In a preferred embodiment, the display and input means for thepersonal digital assistant are configured as an overlaid touch screenand LCD display on a surface of the outer case of the personal digitalassistant. A pointer device implemented as a thumbwheel in oneembodiment and as a pressure sensitive pad in another is provided aspart of the input capability.

[0022] The personal digital assistant module forms a unique combinationwith a general-purpose computer host having the personal digitalassistant as a satellite unit. The host in this instance has a dockingbay especially configured to dock the personal digital assistant, makinga direct bus connection between the local CPU of the personal digitalassistant and the CPU of the host. The host may be a desktop unit, anotebook computer, or a smaller portable like a palmtop computer. Thiscombination provides power and convenience not before available.

[0023] Many other digital devices are also provided according to variousaspects of the invention, such as modems, scanners, data acquisitionperipherals, cellular phones, and a software vending machine, and all ofthese devices may be appended to the personal digital assistant by theexpansion bus interface or, in many cases, by the host interface.

[0024] The personal digital assistant provided according to embodimentsof the present invention is a unit more compact than conventional PDAs.It represents a new dimension in computer application and applicability,in a form promising to be eminently usable by and useful to almosteveryone; and at a price easily affordable. It solves the communicationproblem intrinsic to personal digital assistants relative to larger andmore powerful computers, with a unit that fits into a user's breastpocket, and at a very low price.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1A is an isometric view of a μPDA according to an embodimentof the present invention.

[0026]FIG. 1B is a plan view of the μPDA of FIG. 1A.

[0027]FIG. 2 is a cross-sectional view of the μPDA of FIGS. 1A and 1B.

[0028]FIG. 3 is a block diagram of the μPDA of FIG. 1A and someperipheral elements.

[0029]FIG. 4 is a more detailed plan view of the μPDA of FIG. 1A showingin particular an LCD display and touch screen user interface in anaspect of the present invention.

[0030]FIG. 5 is an isometric view of a μPDA and a host notebook computerin an aspect of the present invention, with the μPDA about to be dockedin a docking bay of the notebook computer.

[0031]FIG. 6 is a block diagram of a μPDA docked in a docking bay of ahost computer according to an embodiment of the present invention.

[0032]FIG. 7 is a logic flow diagram of the steps in docking a μPDA in ahost computer according to an embodiment of the present invention.

[0033]FIG. 8 is an isometric illustration of a μPDA software vendingmachine in an aspect of the present invention.

[0034]FIG. 9 is a top plan view of a μPDA enhanced user interfaceaccording to an embodiment of the present invention.

[0035]FIG. 10 is a top plan view of a μPDA with a microphone in anembodiment of the present invention.

[0036]FIG. 11 is an isometric drawing of a μPDA docked in a dedicatedcellular or cordless telephone according to an embodiment of the presentinvention.

[0037]FIG. 12 is a plan view of a μPDA with a speaker and pagerinterface according to an embodiment of the present invention.

[0038]FIG. 13 is a plan view of a μPDA with an infrared communicationinterface according to an embodiment of the present invention.

[0039]FIG. 14 is a plan view of a μPDA with a scanner attachmentaccording to an embodiment of the present invention.

[0040]FIG. 15 is a plan view of a μPDA with a fax-modem attachedaccording to an embodiment of the present invention.

[0041]FIG. 16 is a plan view of a μPDA with a printer adapter interfaceaccording to an embodiment of the present invention.

[0042]FIG. 17 is an isometric drawing of a μPDA docked in a barcodereader providing a data acquisition peripheral according to anembodiment of the present invention.

[0043]FIG. 18 is an isometric view of a μPDA with a solar chargeraccording to an embodiment of the present invention.

[0044]FIG. 19 is a plan view of four μPDAs interfaced to a dedicatednetwork console providing inter-PDA communication according to anembodiment of the present invention.

[0045]FIG. 20 is an isometric view of a μPDA according to the inventionconnected by the expansion port to a standard-sized keyboard.

[0046]FIG. 21 is a diagrammatical representation of a partiallycompressed BIOS according to an embodiment of the invention.

[0047]FIG. 22 is a flow chart showing the operation of a computer fromstartup following a BIOS routine according to the present invention.

[0048]FIG. 23 is a diagrammatical representation of a tokendecompression scheme according to an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049]FIG. 1A is an isometric view of a μPDA 10 according to anembodiment of the present invention. In this embodiment the unit ismodeled on the PCMCIA standard Type II form factor, having a height D1of about 5 mm. Body 12 is described in further detail below, and has afemale portion 14 of a connector recessed at one end for engaging amating male portion of the connector in a host computer, connecting theμPDA internal circuitry directly with a host internal bus. The host unitmay be a notebook computer having a docking bay for the μPDA. Dockingbays may be provided in desktop and other types of computers, and evenin other kinds of digital equipment, several examples of which aredescribed below.

[0050] Still referring to FIG. 1A, in this embodiment there is acombination I/O interface 16 implemented on one side of the μPDA,comprising a display overlaid with a touch-sensitive planar structureproviding softkey operation in conjunction with interactive controlroutines operable on the μPDA in a stand-alone mode.

[0051] Although not shown in FIG. 1A, there may also be guidesimplemented along the sides of the case of the device for guiding themodule in and out of a docking bay in a host computer unit. There mayalso be one or more mechanical features facilitating engagement anddisengagement of the module in a docking bay.

[0052]FIG. 1B is a top plan view of the μPDA of FIG. 1A, showing athumbwheel 18 implemented in one corner of the μPDA. The thumbwheel inthis embodiment is an input device capable of providing input with bothamplitude and directional characteristics, and in some cases ratecharacteristics as well. The thumbwheel has many uses in combinationwith the μPDA and I/O interface 16. One such use is controlled scrollingof icons, characters, menus, and the like on the display of the device.The thumbwheel provides many of the functions of a pointer device.

[0053] In this embodiment of the μPDA a second external connectorportion 20 is provided. This connector portion is for engagingperipheral devices as part of an expansion bus interface.

[0054]FIG. 2 is a simplified cross-sectional view of a means forconstructing a μPDA according to the present invention in a Type IIPCMCIA, or other relatively small package. ICs 34 are encapsulated in aconformal material 36, and interconnection is accomplished by traces ona flexible polymer film 32 shown as overlaying the encapsulatedstructure. In this structure the ICs are not packaged in theconventional manner having solder leads for assembly to a printedcircuit board. Rather, connections are made directly between the solderpads on the chip and the traces on the Kapton film. Also there is nointention to relate ICs indicated by element No. 34 with specificfunctional ICs in a μPDA. This cross-section is illustrative of a methodof construction only.

[0055] In this compact construction there may also be traces on the sideof film 32 away from the interconnections for the CPU and memory forconnection to other elements, such as display 25 and touch-sensitivescreen 27.

[0056] LCD display 25 is implemented on one side of the μPDA, andtouch-sensitive interface 27 is provided overlaying at least a portionof the LCD display. A metal casing 38, or other suitable material orcombinations of material, surrounds the internal components and conformsto Type II PCMCIA form factors. This simplified cross-sectionillustrates some of the principles of construction that can allow theneeded components to be inexpensively fitted into the small form factorneeded. In another embodiment the μPDA is implemented in the form factorof a type III (10 mm thick) PCMCIA unit, using relatively conventionaltechnology, such as PCB technology, rather than the encapsulatedconstruction described immediately above. Various other constructions,form factors, and combinations are possible, as well.

[0057]FIG. 3 is a simplified electrical block diagram of the μPDA ofFIGS. 1A, 1B and 2. A unique microcontroller 11 acts as the CPU of theμPDA in the stand-alone mode, that is, when the μPDA is not docked in ahost unit. When the μPDA is docked in a host computer, microcontroller11 acts as a slave unit, granting bus control to the CPU of the host. Indocked mode, the CPU of the host thus gains control of the memorycontents of the μPDA, subject in most cases to security procedures whichare described below. Thus the host computer can transfer data andsoftware into and out of a docked μPDA memory. In other embodiments manyother cooperative operating modes may be accomplished between the twoCPUs and accessible memory devices.

[0058] Memory 13 is preferably a nonvolatile device from 1 to 2megabytes in this embodiment, and both control routines for applicationsand data files are stored in this memory. Memory 13 may be flash memory,CMOS ROM, CMOS RAM with battery, or a combination, with the softwarestored in ROM and the data in the flash memory. The memory device isinterfaced to microcontroller 11 via a dedicated bus structure 17, andmicroprocessor 11 is configured to drive memory bus 17.

[0059] A battery 15 is the power source in the stand-alone mode, and maybe recharged in one or more of several ways. The power traces are notshown in FIG. 3, but extend to all of the powered devices in the μPDAmodule. When the unit is docked in the host, the host power source maybe connected to pins through the host interface to recharge the battery.Alternatively, an attached means such as a solar panel may be configuredto charge the battery and/or provide power to the μPDA. A solar panelfor power is described elsewhere in this disclosure. Also the batterymay be easily removed for periodic replacement.

[0060] Host bus connector 14 is a part of a host interface whichcomprises a bus structure 26 for providing connection to the host indocked mode, as described above. In a preferred embodiment, the hostinterface is according to PCMCIA Type II, Rev. 3 standard, which iscapable of communication either in PCMCIA mode or in a mode similar toPCI mode. PCI mode refers to a high-speed intermediate bus protocolbeing developed by Intel Corporation, expected to become a standard busarchitecture and protocol in the industry. The physical interface at thehost in this embodiment is a slot-like docking bay, as is typical ofknow docking bays for PCMCIA devices. This docking bay may beimplemented as a docking box, a built-in unit like a floppy-drive unit,or it may take some other form.

[0061] Connector portion 20 is a part of the expansion bus interfacedescribed above, comprising a dedicated bus structure 40 connected tomicrocontroller 11. This interface can be implemented in a number ofdifferent ways. The purpose of the optional expansion bus interface isto connect to optional peripheral devices, such as a printer, a FAXmodem, a host cellular phone, and others. The expansion bus interface isnot an essential feature in a minimum embodiment of the presentinvention, but provides vastly enhanced functionality in manyembodiments.

[0062] The expansion interface can take any one of several forms. Apreferred form is an extended enhanced parallel port and protocol basedon an invention by the present inventors disclosed in a co-pendingpatent application. Another form is an indexed I/O port having 8-bitaddress and 8-bit data capability. The requirement of the expansion portis that the connection and communication protocol be compatible withexpansion devices, such as telephone modems, fax modems, scanners, andthe like. Many other configurations are possible.

[0063] Optional equipment such as devices listed in box 19 may beconnected for use with the μPDA through the expansion bus. Selected onesof such devices may also be built in to the μPDA in various embodiments,providing variations of applicability. In the former case, connection isthrough path 21 and the expansion bus interface via connector portion20. In the built-in case, connection is in the interconnection traces ofthe μPDA as indicated by path 23.

[0064] I/O interface 16 (also FIG. 1B) is for viewing μPDAapplication-related data and for touch-sensitive input via softkeys. Bysoftkeys is meant assignment by software of various functions tospecific touch sensitive screen areas, which act as input keys. Labelsin I/O interface 16 identify functionality of the touch-sensitive areasin various operating modes according to installed machine controlroutines. LCD display 25 and the touch-sensitive area 27 together formthe combination I/O interface 16 described also above.

[0065] In some embodiments of the present invention, data and programsecurity is provided comprising an Electrically Erasable ProgrammableRead Only Memory (EEPROM) 31, which is connected by dedicatedcommunication lines to microcontroller 11. EEPROM 31 holds one or morecodes installed at the point of manufacturing to provide security forinformation transfer between a host and a μPDA. The purpose is tocontrol access by a host to the memory contents of a μPDA, so each μPDAmay be configured to an individual. To accomplish this, docking and busmastering machine control routines are initiated at the point ofdocking, and this security process is described in more detail below. Inother embodiments, security codes may be provided by a Read Only Memory(ROM) chip or other permanent or semi-permanent memory source.

[0066]FIG. 4 is a plan view similar to FIG. 1B, of a μPDA, showing inparticular I/O interface 16. The size and location of I/O interface 16may vary, but in general occupies a major portion of one of the sides ofthe module. In one embodiment I/O interface 16 comprises an LCD displaywith a resolution of 256 by 144 pixels in a screen size that displays 32by 12 characters. Each character in this embodiment is displayed in anarea eight pixels wide and twelve pixels high. In another embodiment,the pixel resolution is 320 by 200, which corresponds to 40 by 16characters.

[0067] The touch-sensitive areas of the touch-sensitive screencorrespond to the character areas of the display. By touching an areawith a finger or stylus, data can be entered quite quickly and withminimal CPU demand.

[0068] At one corner, thumbwheel 18 provides a two-directional means ofcontrolling the configuration of the display according to installedcontrol routines. A menu 70 is configured at one side to represent thecurrent status of any application in progress and to provide appropriateuser menu selections. In a preferred embodiment input from thumbwheel 18is used for scrolling through menu 70, and active areas may be indicatedby a cursor. A user makes a menu selection by pressing the appropriatetouch-sensitive area. A specific input may be provided to cause the menuarea to be displayed on either side of the display according to a user'spreference.

[0069] Specific characters are displayed in this embodiment in a region74, with each character area associated with a touch-sensitive inputarea. As region 70 dedicated to selectable characters is much too smallto display all characters of a standard keyboard, input from thumbwheel18 allows a user to pan region 74 displaying an entire virtual standardkeyboard. Movement of thumbwheel 18 in one direction pans the characterregion horizontally, and movement in the other direction pans thecharacter region vertically. When an end is reached the window pans ontothe virtual keyboard from the other end. In this manner, a user mayquickly pan the character window to display an entire standard keyboard,and make selections with a finger or a stylus. Of course, it is notrequired that a virtual keyboard be laid out for access in the format ofa standard keyboard. Characters and punctuation, etc., could just assimply be displayed in a single strip along a region of the display, andscrolled by input from the thumbwheel or other pointer-type inputdevice.

[0070] In this embodiment, to avoid delays caused by panning, if thethumbwheel is rotated quickly the character window jumps rather thanscrolling to speed up the interface. In addition, menu 70 may optionallyprovide for a character display in different fonts and sizes, although asingle font is preferred to minimize memory demand. It will be apparentto those with skill in the art that there are many alternatives forcharacter selection and display, and many ways thumbwheel 18 may beconfigured to allow for scrolling and panning.

[0071] A document window 72 is provided in this embodiment at the top orbottom of I/O interface 16. A cursor locates the active position withinthe document for editing purposes. Menu 70 provides selection ofavailable fonts, and input by thumbwheel 18 controls cursor movementover the document. As a document will in almost all cases be much largerthan the display capability of region 72, it is necessary to pan thedocument window in essentially the same manner as the keyboard window ispanned. For example, rotating thumbwheel 18 in one direction may displayhorizontal strips of a document, while rotating the thumbwheel in theopposite direction moves the window vertically strips of the samedocument.

[0072] A soft key or optional hard key may be configured to switchbetween the document and keyboard window, and the same or another keymay be configured to switch between scrolling left or right, up or down,document or keyboard. A switch key may be used to change the thumbwheelmode of operation. A switch key may also be used in combination with afloating pointer to select characters and menu items. In thisembodiment, the user can keep his or her hands relatively stationary onjust the thumbwheel and the switch key, making all possible selections.Use of a switch key in combination with a floating pointer facilitatesthe use of small fonts. A switch key may also be incorporated as anadditional hard key in a convenient location on the case 12.

[0073] It will be obvious to a person skilled in the art than there arenumerous ways to combine menu selections, switching keys and I/Oconfigurations to provide a user-friendly user interface. A furtherembodiment of the present invention provides an I/O set-up applicationwherein a user may completely customize features of I/O area displays.

[0074] There are other sorts of mechanical interfaces which may be usedto provide pointer-style input in different embodiments of the inventionas alternatives to the thumbwheel disclosed. One is a four-wayforce-sensitive mouse button and a selector button, which may be locatedat opposite ends of case 12 below I/O interface 16. Each button isdesigned to be operated by one finger. The four-way force-sensitivemouse button can provide menu scrolling of a cursor and panning and/orindexing of keyboard and document windows, while the selector button isused to select and edit according to position of a cursor. Thisconfiguration minimizes hand movement and keeps the I/O area clear forviewing.

[0075] Implementation of thumbwheels, pressure-sensitive switches andbuttons, and the like, are known in the art, including the translationof mechanical motion and pressure to electrical signals and provision ofsuch signals to a microcontroller. For this reason, details of suchinterfaces are not provided in this disclosure. Combinations of suchinputs with displays and input areas may, however, be considered asinventive.

[0076]FIG. 5 is an isometric drawing of a μPDA 10 in position to bedocked in a notebook computer 172 via a Type II PCMCIA docking port 105according to an embodiment of the present invention. As furtherdescribed below, once the μPDA is docked, it is activated and aprocedure is initiated with the host computer to manage communicationand verify memory access rights (security).

[0077] Access rights are considered important by the inventors for anumber of reasons. Firstly, through the expedient of one or morespecific codes, unique to each μPDA, a user may protect files stored inhis module from access by unauthorized persons. The code can be usedboth to control access to data and files via I/O interface 16, and alsothrough the host bus interface, so data and files may be secure fromaccess by an unauthorized host system.

[0078] In the former case, when a μPDA is powered up, an applicationroutine can query the user for an access code to be entered at I/Ointerface 16 FIG. 4). If the code is not entered properly, access isdenied, and power goes off. Codes for the purpose are stored in EEPROM31 (FIG. 3), or in whatever ROM device may be devoted to the purpose. Insome embodiments, the code may by mask-programmed at manufacture, so itis not alterable. In others, the code may be accessible and changeableby special procedures in the field.

[0079] In the case of host communication, it is possible that a portableor desktop computer, or some other device, may have a docking portphysically configured to receive a μPDA, yet not be configured tocommunicate with the μPDA. This certainly might be the case where theμPDA is in the PCMCIA form. For purposes of disclosure and description,this specification terms such a unit a generic host. If the unit isconfigured to communicate with a μPDA it is an enabled host. If a hostis configured for full access to a particular μPDA, it is a dedicatedhost.

[0080] If a docking unit is a generic host, there will be nocommunication unless the person presenting the μPDA provides the controlroutines to the host. This may be done for a generic host such as bytransfer from a floppy disk, from a separate memory card through thedocking port, or, in some embodiments, the communication software may beresident in memory 13 (FIG. 3) of a docked μPDA, transferable to thehost to facilitate further communication.

[0081] If the docking unit is in fact an enabled host, or is configuredafter docking to be an enabled host, the stored code or codes in EEPROM31 (or other storage unit) may be used to verify authorization for dataand program transfer between the host and a μPDA. In one embodiment thisprocedure is in the following order: First, when one docks a μPDA in acompatible docking port, certain pin connections convey to both the μPDAmicrocontroller and to the host CPU that the module is docked. Assumingan enabled host, the fact of docking commences an initializationprotocol on both systems.

[0082] In most embodiments, if the docking unit is a non-host, that is,it is not capable of communication with the docked module, nothinghappens, and the user may simply eject the docked module. If thecomputer is an enabled host, an application is started to configure hostaccess to the μPDA's data files through the μPDA microcontroller. A userinterface, described more fully below for a particular embodiment, isdisplayed on the host monitor 104 (FIG. 5). The host interface menu, aswell as other application menus, may be formatted in part as a displayof the μPDA I/O interface 16 as seen in FIG. 4 and described inaccompanying text. In some embodiments, the docked μPDA can be operatedin situ by manipulating the input areas of the μPDA displayed on thehost's screen.

[0083] If the host is not a home unit for the docked module, that is,the host does not have matching embedded ID codes to those stored in thedocked module, a visitor protocol is initiated. In this event, a visitormenu is displayed on host display 104 for further input, such aspassword queries for selections of limited data access areas in thedocked module. In this case, too, a user may gain full access to thedocked module's memory registers by entering the proper password(s).

[0084] If the host is a fully compatible host home unit, full access maybe immediately granted to the host to access memory contents of thedocked module, including program areas; and both data and programs maybe exchanged.

[0085] In any case, when the μPDA is ejected or otherwise removed fromthe docking port, the on-board module microcontroller again gains fullcontrol of the internal μPDA bus structures.

[0086]FIG. 6 is a simplified block diagram of a μPDA docked in a hostcomputer, and FIG. 7 is a basic logic flow diagram of the steps involvedin docking a μPDA in a host computer 66 according to an embodiment ofthe present invention. Host computer 66 is represented in a mostlygeneric form, having a host CPU 24, and input device 60, such as akeyboard, a mass storage device 28, such as a hard disk drive, andsystem RAM 62. It will be apparent to those with skill in the art thatmany hosts may have a much more sophisticated architecture, and thearchitecture shown is meant to be illustrative.

[0087] When a μPDA unit is docked, connector 14′ in FIG. 6 comprisesportion 14 shown in FIGS. 1B and 3 and a mating connector portion forengaging portion 14 in port 105 (FIG. 5). The engagement of the separateportions of the connector cause bus 26 in the μPDA and bus 26′ in thehost to become directly connected. There is then a direct bus pathbetween microcontroller 11 and host CPU 24 (FIG. 6).

[0088] As previously described there is a pin configuration (not shown)in connector 14 dedicated to signaling that a module is docked. In FIG.7, step 42 represents insertion of a μPDA module into the docking port.At step 44 the signaling pin configuration signifies physical docking isaccomplished. At step 46 host interface bus 26 is activated, includingthe mated host bus 26′ in the host.

[0089] At step 48 (FIG. 7) microcontroller 11 in the μPDA starts apreprogrammed POST procedure. Microcontroller 11 in this embodiment hasa page of RAM 68 implemented on the microcontroller chip. In otherembodiments RAM may be used at other locations. At step 50, the POSTroutine loads a bootstrap program to RAM 68, which includes a code orcodes for security matching. This code or codes comprise, for example, aserial number.

[0090] At step 54 the bootstrap program begins to execute inmicrocontroller 11, and at step 56 the microcontroller looks for apassword from the host on host interface bus 26 (FIG. 6).

[0091] The fact of docking, assuming an enabled or dedicated host, alsocauses a communication routine, which may be accessed from, for example,mass storage device 28 at the host, to display a user interface onmonitor screen 104 of the host unit, as partly described above. It isthis communication program that makes a generic host an enabled host.

[0092] Assuming an enabled, but not dedicated, host, the user interfacewill query a user for input of one or more passwords, after successfulentry of which the host will pass the input to microcontroller 11 forcomparison with the serial number and perhaps other codes accessed fromEEPROM 31 in the bootstrap of the μPDA.

[0093] According to the codes passed from the host to the docked module,microcontroller 11 will allow full access to memory 31 at function 52,FIG. 7, for the host CPU, or limited access at some level at function58, defined by received codes (or no matching code at all).

[0094] The access protocols and procedures allowing partial or directaccess to μPDA memory 13 are relatively well known procedures in theart, such as bus mastering techniques, and need not be reproduced indetail here. In addition to simple comparison of codes, there are othertechniques that may be incorporated to improve the integrity of securityin the communication between a μPDA and a host. For example, within thelimitation of storage capacity of the EEPROM or other nonvolatilesource, executable code might also be uploaded to onboard RAM 68, orcode keys to be used with executable code from other sources, orrelatively simple maps re-allocating memory positions and the like, soeach μPDA may be a truly unique device.

[0095] There are additional unique features provided in one aspect ofthe invention as part of the communication routines introduced above.One such feature is automatic updating and cross-referencing of existingfiles and new files in both computers, under control of the host system,with the host having direct bus access to all memory systems.Auto-updating has various options, such as auto-updating by clocksignature only, flagging new files before transfer, and an editing meansthat allows the user to review both older and newer versions of filesbefore discarding the older in favor of the newer. This automatic orsemiautomatic updating of files between the satellite and the hostaddresses a long-standing problem. The updating routines may alsoincorporate a backup option to save older files.

[0096] Another useful feature in host/μPDA communication is a means fora user to select and compose a mix of executable program files fordownloading to a μPDA, either replacing or supplementing thoseexecutable routines already resident. A user can have several differentprogram lists for downloading as a batch, conveniently configuring theapplicability of a μPDA among a wide variety of expected workenvironments.

[0097] Such applications as databases, spreadsheets, documents, travelfiles such as currency converters, faxing and other communicationsprograms, time clocks, address and telephone records, and the like, maycomprise customized lists of user-preferred applications.

[0098] In another embodiment, an undocked μPDA can transfer data via theoptional expansion bus 40 (FIG. 3) directly to a host. In the specialcase of a μPDA user without access to a PCMCIA interface on his host(notebook or desk-top) computer, he or she can connect to a host via anauxiliary port on the host, such as a serial port, via the expansion businterface. In this case, the μPDA still requests password(s) from thehost, and controls access to its on-board memory according to thepassword(s) received.

[0099] The optional expansion interface may also be used in someembodiments while a μPDA is mastered by a host, wherein the host mayeffectively send data through the bus structures of the μPDA.

ADDITIONAL ASPECTS AND FEATURES

[0100] Software Vending Machine:

[0101] In a further aspect of the invention, a Software Vending Machinewith a very large electronic storage capacity is provided, wherein aμPDA user may dock a module and purchase and download software routinescompatible with the μPDA environment.

[0102]FIG. 8 is an isometric view of such a vending machine 61 having adocking bay 63 for a μPDA, a credit card slot 65, and a paper money slot67. A display 69 provides a user interface for reviewing and purchasingsoftware from the vending machine, along with selector buttons such asbutton 71 along the sides of the display. In an alternative embodimentthe display may also have a touch screen, and may, in some embodiments,emulate the μPDA I/O area on a larger scale.

[0103] In operation, a user may, in this embodiment, review software forsale simply by docking his μPDA unit in the vending machine andselecting from a menu on display 69. The menu may allow the user tobrowse all available applications, or list new applications sinceentered dates. The user can select certain applications, try them out,at least in simulation, and then select applications to purchase.

[0104] The vending machine, once all the requirements are met, such asproper identification and payment, copies the selected application(s) tothe memory of the μPDA, or, alternatively, to a floppy disk provided byeither the user or the vending machine. In this case there is also afloppy disk drive 73 in the vending machine and a port 75 for dispensingformatted floppies for a customer to use in the disk drive. This mode isuseful for the instances where a user's μPDA is loaded beyond capacityto receive the desired software, or the user simply wishes to configurethe software mix himself from his or her own host computer.

[0105] There may also be provided a backup option so a user may instructthe vending machine to read and copy all or a selection of his files toone or more floppy disks before installing new files or data.

[0106] As described above, each user's μPDA includes an EEPROM or otherstorage uniquely identifying the μPDA by a serial number or othercode(s), so the vending machine may be configured in this embodiment toprovide the software in one of several modes.

[0107] A user may buy for a very nominal price a demo copy of anapplication, which does not provide full capability of the application,but will give the user an opportunity to test and become familiar withan application before purchase. Also, the user may buy a version of thesame application, configured to the ID key of the μPDA to which it isloaded, and operable only on that μPDA. In another embodiment, thesoftware is transferable between a family of keyed μPDAs, or has theability to “unlock” only a limited number of times. In these cases, theapplications would be sold at a lesser price than an unlocked version.The unlocked version works on any μ-PDA and/or host/μPDA system. Thehigher price for the unlocked version compensates for the likelihood ofunauthorized sharing of the vended applications.

[0108] The vending machine could also offer a keyed version, customizedto operate only on the μPDA docked in the software vending machine, orupon a family of μPDAs. This keyed version is possible because of theindividual and unique nature of each μPDA, which has, at a minimum, aunique serial number, and may also have other security programming, asdescribed above, which allows a vending machine to prepare and downloada customized copy of an application that will operate only on theparticular module for which it is purchased.

[0109] There are a number of different means by which uniquecorrespondence might be accomplished, as will be apparent to those withskill in the art. A standard version stored in the memory facility of avending machine might be recompiled, for example, on downloading, usinga unique code from the docked or identified μPDA as a key in thecompilation, so only the specific μPDA may run the program by using thesame unique key to sequence the instructions while running. The key forscrambling or otherwise customizing an application might also compriseother codes and/or executable code sequences stored uniquely in a μPDA.

[0110] In yet another aspect related to the vending machine, there is aprinter outlet 77 which prints a hardcopy manual for the user. It is, ofcourse, not necessary that the software vended be specific to the M-PDA.Applications may also be vended for other kinds of machines, andtransported in the memory of the μPDA, or by floppy disk, etc. In thisembodiment a non-μPDA user can acquire a wide assortment of software.

[0111] The software vending machine may also serve as an optionalinformational display center in such locations as airports, trainstations, convention centers, and hotels. Upon inserting a μPDA a usermay interface directly and upload current information including, but notlimited to, local, national, and world news; stock quotes and financialreports; weather; transportation schedules; road maps; languagetranslators; currency exchange applications; E-mail and other directon-line services.

[0112] A customized vending machine could be tailored to businesstravelers and allow fast access to pertinent information, allowing theuser to download files to send via E-mail. In another aspect of theinvention, the vending machines are linked to each other allowing usersto send messages to associates traveling through locations of associatedvending machines. Such dedicated μPDA E-mail is immediately downloadedto a specific μPDA as it is docked. The sender may have the associate'sμPDA unique encoded key as identification, or some other dedicatedidentifying means for E-mail.

[0113] In another embodiment, as each business associate arrives at anairport, he or she may prompt the custom vending machine in thatlocation via an optional installed infrared interface (not shown) intheir μPDA. The custom vending machine, also equipped for infraredcommunication, receives the signal and sends/or receives any messagesthat are waiting.

[0114] Enhanced Display:

[0115]FIG. 9 is a plan view of an enhanced I/O interface unit 79according to an aspect of the present invention. Interface unit 79, withabout a 5-inch diagonal measurement, comprises a combination LCD displayat least partially overlaid by a touch-sensitive input screen, providingan I/O area 80 in much the same manner as in a μPDA. Four docking bays81, 83, 85, and 87 are provided in the left and right edges of interfaceunit 79 in this embodiment, and are configured for PCMCIA type IImodules. One of these bays may be used for docking a μPDA according tothe present invention, and the other three to provide a larger CPU,additional memory, battery power, peripheral devices such as modems, andthe like by docking functional PCMCIA modules.

[0116] Interface unit 79 is a framework for assembling a specialtycomputer through docking PCMCIA units, including a μPDA according to thepresent invention. In other embodiments where the μPDA assumes otherform factors, the docking bays may be configured accordingly.

[0117] A docked μPDA in this embodiment is configured to produce its I/Odisplay on I/O area 80. The thumbwheel on the M-PDA is accessible whiledocked and acts as described above in the stand-alone mode in this case.In another aspect, the enhanced display has a re-configured output thatenables the user to manipulate the data from the touch-screen aloneand/or additional hardware selector buttons and/or a standard keyboardattached to the enhanced display via a dedicated bus port, or eventhrough the expansion port of a docked μPDA. In a further embodiment theenhanced display has a dedicated mouse port and/or a dedicatedthumbwheel.

[0118] In yet another embodiment, interface unit 79 has an inexpensive,conventional, replaceable battery and/or a rechargeable battery. Also,in another aspect, interface unit 79 may dock two or more individualμPDAs and cross-reference data files between them according to controlroutines that can manipulate mutually unlocked files. Further still,interface unit 79 may be placed and structurally supported for easyviewing on a dedicated standard or smaller-sized keyboard, connecting tothe keyboard as an input device. The keyboard would then automaticallyserve as the input device.

[0119] Interface unit 79 for a μPDA is small and compact enough to slipinto a pocket book or briefcase, providing a very portable, yet verypowerful, computer.

[0120] Microphone/Voicenotes:

[0121]FIG. 10 is a plan view of a μPDA 110 with an I/O interface 116, anexpansion port 120, and a host interface connector 114. μPDA 110 has allthe features previously described and additionally a microphone 88. Inthis embodiment, control routines in the μPDA use a linear predictivecoding (LPC) approach to convert analog input from the microphone to adigital voice recording. This approach uses a minimum of memory, butstill is capable of reproducing audio input like the human voice withinrecognizable limits.

[0122] In an alternative embodiment, for better quality voice recording,a two-step integrator may be used in order to separate the analog signaland synthesize a closer digital representation.

[0123] With a μPDA so configured, a user's voice notes can be recordedand later uploaded to a host for processing. In future embodiments thedigital signals may be converted to text or sent as voicemail on anetwork. In yet another embodiment, the microphone is integrated with aspeaker for editing purposes.

[0124] Cellular Telephone Interface:

[0125]FIG. 11 is an isometric view of a μPDA 10 docked in a dedicatedcellular telephone 45 according to an embodiment of the presentinvention. Telephone 45 has a docking port 49 for a μPDA according tothe invention. In this embodiment, port 49 is on one side of telephone45, and there is a window 51 to provide access to I/O interface 16 ofthe μPDA after it is docked. With the μPDA docked, all of the softwareand memory of the μPDA is available to the telephone and a user mayoperate the phone by I/O interface 16.

[0126] In this aspect of the invention, unique control routines anddisplay configurations are provided to enhance use of the cellularphone. For example, all of the user's collection of phone numbers,associated credit card numbers, access codes, etc. are readily availableand may be quickly and conveniently accessed and used. In one aspect, asimple input displays alphabet letters to select, and once a letter isselected, a partial list of parties that might be called is displayed.One may scroll through the list by touch input or by use of thethumbwheel of the μPDA and select a highlighted entry. It is notrequired that the telephone numbers be displayed.

[0127] Once a party to be called is selected, the μPDA dials the call,including necessary credit card information stored in the memory of theμPDA for this purpose.

[0128] In a further embodiment, the calls are timed and time-stamped anda comprehensive log, with areas for notes during and after, is recorded.

[0129] In another embodiment, conversations are digitally recorded andfiled for processing later. A future embodiment may include a voicecompression program at a host or within cellular phone 45. Compressedvoice files, such as, for example, messages to be distributed in avoicemail system, may be downloaded into the μPDA or carried in a largermemory format inside the cellular telephone. The μPDA can then send thefiles via a host or dedicated modem attached at connector portion 20 tothe optional expansion bus 40 (FIG. 6).

[0130] The cellular telephone may, in this particular embodiment, have abus port for digital transmission. In this case, the compressionalgorithm along with voice system control routines are also establishedat the receiving end of the transmission to uncompress the signal anddistribute individual messages.

[0131] In a further embodiment, voice messages may be sent in a wirelessformat from the cellular telephone in uncompressed digital synthesizedform, distributing them automatically to dedicated receiving hosts, orsemi-automatically by manually prompting individual voicemail systemsbefore each individual message. In a further aspect of wirelesstransmission, a microphone/voicenote μPDA as in FIG. 10 may sendpreviously stored voicenotes after docking in a cellular telephoneinterface.

[0132] In Europe and Asia a phone system is in use known as CT2,operating on a digital standard and comprising local substations where aparty with a compatible cellular phone may access the station simply bybeing within the active area of the substation. In one aspect of thepresent invention, a CT2 telephone is provided with a docking bay for aμPDA, and configured to work with the μPDA. In yet another aspect of theinvention, in the CT2 telephone system, and applicable to other digitaltelephone systems, a compression utility as disclosed above is providedto digitally compress messages before transmission on the CT2 telephonesystem.

[0133] It is roughly estimated that a dedicated compression algorithmmay compress ten minutes of voice messages into one minute using theexisting CT2 technology. This would save on telephone use chargessignificantly. In this aspect, there needs be a compatible decompressionfacility at the receiving station, preferably incorporated into astandard μPDA voicemail system for CT2 or other digital transmissions.

[0134] In a further embodiment, control routines are provided to enablethe microphone/voicenote μPDA as illustrated in FIG. 10 to carry digitalvoicenotes, either compressed or uncompressed. When docked in aCT2-compatible μPDA cellular telephone, the μPDA in this embodiment cantransmit the digital voicenotes in compressed form.

[0135] Speaker/Pager:

[0136]FIG. 12 is a plan view of a μPDA 210 with a microphone/speakerarea 90 and a pager interface 92 according to an embodiment of thepresent invention. This μPDA has the ability to act as a standard pager,picking up pager signals with installed pager interface 92 and alertinga user through microphone/speaker 90. Once the signals are received,μPDA 210 can be docked in a compatible cellular telephone as illustratedin FIG. 11 and the μPDA will automatically dial the caller's telephonenumber. All other aspects are as described in the docked mode in thecellular telephone.

[0137] In another embodiment, the speaker/pager μPDA can be prompted togenerate DTMF tones. The DTMF tones are generated from a caller'stelephone number.

[0138] The speaker/pager μPDA can store pager requests in its onboardmemory. It can also display all pager requests including time and datestamps, identification of the caller, if known, and other relatedinformation, on I/O interface 216. In this particular embodiment, a usercan receive a page, respond immediately in digital voicenotes on theμPDA via speaker/microphone 90, and then send the response from adedicated μPDA-compatible cellular telephone or conventional telephone.

[0139] Wireless Infrared Interface:

[0140]FIG. 13 is a plan view of a μPDA 310 with an IR interface 94according to an embodiment of the present invention. In this embodimentthe μPDA may communicate with an array of conventional appliances in thehome or office for providing remote control. Unique signals for theappliances are programmed into the μPDA in a learning/receive mode, andfiled with user password protection. Once a correct password in entered,an icon-based menu is displayed on I/O area 316 in a user-friendlyformat. A master routine first queries a user for which device toaccess. For example, in a residential application, icons are displayedfor such things as overhead garage doors, security systems, automaticgates, VCRs, television, and stereos.

[0141] In another aspect of the invention, a receiving station such as ahost computer or peripheral interface has IR capabilities to communicatedata directly from a nearby μPDA with an infrared interface. In afurther embodiment the μPDA may interface in a cellular network and actas a wireless modem.

PERIPHERALS

[0142] A μPDA may serve as the platform for various peripheralattachments via expansion port 20 (FIG. 1B and others). Upon attachmentto a peripheral, a dedicated pin or pins within expansion port 20 signalmicrocontroller 11, and a peripheral boot-strap application is executed.Interfacing control routines, which may reside in the peripheral or inthe memory of the μPDA, are then executed, and the μPDA I/O interfacedisplays the related menu-driven options after the linking is complete.

[0143] Scanner:

[0144]FIG. 14 is a plan view of a μPDA 10 with a scanner attachment 55according to an embodiment of the present invention. The scannerattachment is assembled to the μPDA, making electrical connection viaexpansion port 20. In this embodiment the physical interface of thescanner is shaped to securely attach to the μPDA. Scanner attachment 55has a roller wheel 57 or other translation sensor, which interfaces withwheel 18 of the μPDA, providing translation sensing in operation for theresulting hand-held scanner. In another aspect, scanner attachment 55has a translation device which transmits the proper signal throughexpansion port 20. The scanner bar is on the underside, and one or morebatteries 59 are provided within the scanner attachment to provide theextra power needed for light generation.

[0145] In the scanner aspect of the invention, scanner attachments 55 ofdifferent width D2 may be provided for different purposes. The bar maybe no wider than the μPDA, or may be eight inches or more in width toscan the full width of U.S. letter size documents, or documents oninternational A4 paper. Unique control routines display operatinginformation on the μPDA's I/O area 16 for scanning, providing a userinterface for setup of various options, such as the width of the scannerbar, and providing identification for files created in the μPDA memoryas a result of scan passes. Scanned data stored in the μPDA memory maybe quickly transferred to the host via host interface 14 when the μPDAis docked. Unique routines may be provided to automate the process, sothe user does not have to search for files and initiate all of thetransfer processes.

[0146] Facsimile Option:

[0147]FIG. 15 is a plan view of a μPDA with a fax-modem module 89attached according to an embodiment of the present invention. A fax andtelecommunication capability is provided via conventional telephonelines to the μPDA by fax-modem 89 interfacing to expansion bus interface20. The fax-modem has internal circuitry for translating from the busstates of the expansion bus to the fax protocol, and a phone pluginterface 91. In another aspect, the μPDA can be docked in a host and beused in combination with fax-modem 89 to provide faxing and filetransfers of both host and μPDA data files. In this case, the fax-modemroutines are displayed on the host monitor.

[0148] Printer:

[0149]FIG. 16 is a plan view of a μPDA with a Centronics adapterinterface according to an embodiment of the present invention. A printerconnector 93 engages expansion interface 20 by a connector 95 through acable 97. Translation capability resides in circuitry in connector 93,which is configured physically as a Centronics connector to engage astandard port on a printer.

[0150] Barcode Reader and Data Acquisition Peripheral:

[0151]FIG. 17 is an isometric view of a μPDA 10 docked in a barcodereader and acquisition peripheral 100 according to an embodiment of thepresent invention. μPDA 10 is docked in docking bay 149. I/O interface16 displays information through opening 147 according to specializeddata acquisition applications. In this particular embodiment peripheral100 has an IR interface 94, a microphone 103, a scanner port 101 (notshown), battery pack 105, and a numeric keypad pad 96 implemented as atouch-sensitive array.

[0152] Application routines enable the data acquisition peripheral tooperate as, for example, a mobile inventory management device. The usermay scan barcode labels with scanner 101 and enter information, such ascounts, on keypad 96 or by voice input via microphone 103. Sinceapplications of peripheral 100 are very specialized, only a limitedvoice recognition system is needed. The voice recognition system mayprompt other command routines within the master applications as well.

[0153] As inventories are collected, the database may be displayed andalso manipulated directly via I/O area 16 in open bay 147, orinformation may be downloaded at a prompt to a nearby host via IRinterface 94.

[0154] Alternatively to frequent data transmission, data may be storedor an auxiliary option memory location in peripheral 100.

[0155] In another aspect, the data acquisition peripheral may beinterfaced to the analog output of a monitoring device, such as a stripchart recorder, and may digitize and store the incoming analog signals.

[0156] Solar Charger:

[0157]FIG. 18 is an isometric view of the side of a μPDA 10 opposite theI/O interface with a solar charger panel 98 according to an embodimentof the present invention. Panel 98 is positioned so that when μPDA 10 isin strong light, such as sunlight, the solar charger absorbs the solarenergy and converts it to electricity to recharger battery 15 inside theμPDA. Solar charger 98 may be permanently wired to the circuitry of theμPDA or attached by other means and connected to a dedicated electricalport or the expansion port. The solar charger is placed so that the μPDAcan be fully docked in a docking port with the panel in place. Inanother aspect, a detachable solar charger may be unplugged beforedocking the μPDA, and the detachable charger may then be of a largersurface area.

[0158] Games/Conference Center:

[0159]FIG. 19 is a largely diagrammatic representation of a Games Centerunit 33 according to an aspect of the invention for connecting severalμPDA units (37, 39, 41, and 43) together to allow competitive andinteractive games by more than one μPDA user. Games Center unit 33 iscontrolled by an 80486 CPU in this particular embodiment. μPDAs may beconnected to the central unit by cable connection via the expansion busor the host interface of each μPDA, through a connector such asconnector 35. The drawing shows four connectors, but there could be asfew as two, and any convenient number greater than two.

[0160] As a further aspect of the present invention, the gaming centermay serve as a conference center where a number of μPDAs may exchangeinformation. In this way, for example through custom routines stored andexecutable in central unit 33, a manager may update a number ofsalespeople's μPDAs, including but not limited to merchandise databases,spreadsheets, price sheets, work assignments, customer profiles, addressbooks, telephone books, travel itineraries, and other related businessinformation while in conference.

[0161] Standard Keyboard:

[0162]FIG. 20 is an isometric view of a keyboard 151 connected by a cordand connector 153 to a μPDA 10 via the expansion port 20. In thisexample, the keyboard is a mechanical keyboard having a full-sizestandard key array and an on-board controller and interface forcommunicating with the μPDA. In other embodiments the keyboard may takemany other forms, including a two-layer, flexible, roll-up keyboard astaught in U.S. Pat. No. 5,220,521.

[0163] In addition to keyboards, other input devices, such as writingtablets and the like may also be interfaced to a μPDA via expansion port20.

[0164] There are numerous additional ways to combine differentembodiments of the μPDA for useful functions. For example, anIR-equipped μPDA attached to scanner 55 may transfer large graphic filesin near real time to a host computer. If the files were of text, thehost may further process the files automatically through an opticalcharacter recognition (OCR) application and send the greatly reducedASCI files back to the μPDA. As discussed above, the μPDA family ofdevices establishes a protocol of software security and distribution aswell as having the ability to be bus mastered by a host computer systemfor numerous applications.

[0165] Compressed BIOS:

[0166] As was described above in the Background” section, it would bedesirable to be able to provide for a μPDA according to an embodiment ofthe invention, from a ROM device of fixed storage capacity, moreapparent lines of operable code than could ordinarily be provided from aROM of that storage capacity. A compressed BIOS system is describedbelow for just this purpose, wherein a BIOS code routine is stored in acompressed portion of a ROM along with an uncompressed portionconfigured for testing and initializing system memory on startup, and anuncompressed portion comprising a decompression utility configured todecompress the compressed ROM portion.

[0167] In most BIOS systems for general-purpose computers, the BIOS isstored in an EPROM device. Upon power up the BIOS initializes thesystem, doing basic tasks like accessing and checking the operation ofon-board random-access memory RAM, and typically, somewhere during theinitialization, at least a part of the BIOS code is copied (the BIOScopies itself) into a portion of the on-board RAM, although this step isnot required, as BIOS routines may be executed directly from the EPROMdevice.

[0168] The portion of RAM reserved for BIOS code in a computer isgenerally termed “shadow” RAM. The term shadow RAM is also used in theindustry for a particular hardware type of memory device wherein eachvolatile memory cell has a connected non-volatile (EPROM-type) cell.These are more properly called NVRAM devices, and are not what is meantin this description by shadow RAM. Shadow RAM for the purpose of thisdisclosure is simply that portion of RAM reserved for a copy of part orall of the BIOS code.

[0169] In typical general-purpose computers, as soon as the systemreceives power, the BIOS tests and initializes system RAM, then copies(shadows) itself from the EPROM to the RAM. The BIOS continues to run inRAM. The purpose of shadowing the BIOS in RAM is to give the CPUmicroprocessor much faster access to the BIOS code than it would have byaccessing the EPROM every time a BIOS code sequence is needed incontinuing operations.

[0170] The present invention comprises a means of compressing at least asignificant portion of the BIOS code, storing all of the BIOS code,including the compressed portion, in EPROM, and releasing the compressedcode on powerup, so all of the code is available for the computer touse. Also on powerup, the entire code is shadowed to RAM.

[0171]FIG. 21 is a diagrammatical representation of a compressed BIOS1011 according to the present invention. There are three differentportions of the code. Portion 1013 is code to perform all operations toinitialize and test the system RAM, and make it ready for use, and is afamiliar portion of conventional BIOS routines. This portion in someapplications needs to perform such functions as initializing and testinga memory controller and cache controllers and cache memory. Portion 1015is a decompression utility. Portion 1017 represents the balance of theBIOS code in compressed form. It will be apparent to those with skill inthe art that there are a number of compression schemes and relateddecompression routines that might be used.

[0172]FIG. 22 is a flow chart showing the operation of a computer fromstartup following a BIOS routine according to the present invention.From powerup signal 1019, which is typically derived from the act ofclosing the power on switch, operation goes to initialization operation1021, during which system RAM is initialized. In operation 1021, thesystem runs portion 1013 of FIG. 21.

[0173] Next, decompression utility 1015 (FIG. 21) is accessed and run inoperation 1023. The decompression utility processes the balance of theBIOS code (compressed), translates it into operable code, and shadows itto system RAM. Although such decompression utilities are available, thecode pointing to the compressed portion of the BIOS, and that whichcauses the decompressed code to be shadowed to RAM is not a part of aconventional decompression routine. These commands are added to the BIOSof the invention.

[0174] After the BIOS is shadowed operation continues (1025) from theBIOS in system RAM. All remaining BIOS processes, including testing andinitializing the remainder of the computer subsystems are accomplishedin this operating portion.

[0175] One means by which the BIOS code may be compressed is based onthe fact that BIOS routines, as is common in most other codedinstruction sets, make use of frequently repeated code sequences. EPROMsused for BIOS are typically byte-wide devices, that is, the device canstore “words” of 8 bits. A sixteen bit word requires, then, two lines ofBIOS code.

[0176] In this embodiment frequently repeated code sequences arereplaced in the compressed portion of the BIOS with a token. The tokenin this embodiment is a two byte code in which the first byte is a flagto the decompression utility that the following byte is a pointer. Thepointer portion is an entry to a table which is a part of thedecompression utility, and points to the specific, oft repeated, codesequence. In a simple such system, the table might have but one entry.

[0177] As an example, a frequently repeated code sequence in a BIOSmight be a “call keyboard” sequence, which for the purpose of thisexample, may be eight lines of code. The token could be two lines ofcode in which the first line is the binary representation of thehexadecimal “FF”. In this scheme, hex FF is a flag indicating that thefollowing byte is a pointer. The pointer, then, can be any valuerepresentable by a digital byte, that is any one of 256 values. Therequirement is simply that the decompression utility associate thepointer with the oft-repeated BIOS code sequence, and substitute thatsequence in decompression and copying the BIOS code to RAM. In thisscheme an oft-repeated code sequence need be stored only once in theBIOS portion that is the decompression utility.

[0178]FIG. 233 is a diagrammatical representation of the tokendecompression scheme described above. After the BIOS according to theembodiment of the invention has initialized and tested the RAM, thedecompression utility is booted, and begins to read the compressedportion of the BIOS at Start 1027. At 1029 the decompression utilityloads the first/next byte from the compressed portion of the EPROM BIOS.If this byte is hex FF (1031), it is recognized as a token, and controlgoes to 1033, where the system reads the byte following the token flag.This byte is always a pointer to a code sequence.

[0179] At 1035 the system associates the pointer byte with the codesequence from a preprogrammed table and loads the associated sequence.At 1037 the system copies the n lines of code pointed by the pointerbyte to the next n lines in shadow RAM. Control then goes to decisionpoint 1039 and determines if the last loaded byte from compressed BIOSwas the last byte. If so, control jumps to a predetermined entry pointin the decompressed shadow RAM, and the BIOS routine continues. If not,control goes back to 1029 and the next line of compressed code isloaded.

[0180] At decision point 1031, if the hex value is not FF, the code lineloaded from compressed BIOS is copied directly into the next line inshadow BIOS.

[0181] It will be apparent to one with the skill in the art that thereare many changes that might be made and many other combinations thatmight be made without departing from the spirit and scope of theinvention. There are, for example, many ways to implement the supportstructure of the μPDA, and to interconnect the active components. Oneway has been illustrated by FIG. 2 and described in accompanying text.There are many alternatives to this preferred structure. There is also abroad range of sizes and form factors that might be assumed by devicesaccording to the present invention. The use of well-known PCMCIA formfactors has been disclosed, but other sizes and forms might also beprovided in alternative embodiments. In larger embodiments, on-boardperipherals may be implemented.

[0182] In addition to these alternatives, there are various ways theconnectivity of a μPDA bus might be provided. The well-known PCMCIAstandard has been disclosed as a preference, but other connectivity mayalso be used in alternative embodiments. Memory types and sizes mayvary. Means of providing a security code may vary. The nature of theinternal bus may vary. There are indeed many variations that do notdepart from the spirit and scope of the invention.

[0183] In addition to the above, there are many non-volatile memories inwhich a compressed BIOS may be stored, retrieved, and decompressed, andseveral of these have been listed above. The fact of compressing theroutines in the BIOS, including a loadable decompression routine,extends the capacity of any such finite non-volatile memory devices andhence the size of a BIOS routine that may be stored thereon.

[0184] It is also true that there are a truly large number ofcompression schemes that might be employed to compress a portion of theBIOS. The invention should not be limited by the specific coderelationship determined to compress the BIOS code.

What is claimed is:
 1. A digital assistant module that interfaces with ahost computer, comprising: an on-board CPU that manages functions of thedigital assistant module; a memory connected to the CPU that stores dataand executable routines; a user-operable input apparatus; a hostinterface adapted so as to provide communications between the digitalassistant module and the host computer upon docking with the hostcomputer, said host interface cooperating with a host interface of saidhost computer whereby a user of said host computer may selectpre-arranged software mixes for loading into said memory; and anenclosure that houses said CPU, said memory, said input apparatus, andsaid host interface.